Because rectangular conductor wire is used instead of round wire, edgewise coils that are produced by winding into edgewise windings have advantages such as improving space factor, and lowering resistance values. In addition, because they are not wound into multiple layers, edgewise coils also have advantages such as reducing internal and external differences in coil temperature, and having good heat radiating characteristics.
However, when a rectangular conductor wire is wound into an edgewise winding, outer peripheral portions are stretched, and compressive stresses act on inner peripheral portions. The inner peripheral portions have a tendency to bulge due to the action of the compressive stresses. An insulating coating such as enamel is generally coated onto the surface of the rectangular conductor wire.
In conventional edgewise coil constructions, in which bending is applied at identical positions so as to be arranged neatly, the inner peripheral bulging portions due to bending overlap in a direction of lamination of the coils, and there has been a risk that insulation between the wire of the coils may deteriorate.
In consideration of such conditions, rotary electric machines have been proposed that include: a first bent portion to which bending is applied, and that constitutes a coil end portion; and a second bent portion that is disposed adjacent to the first bent portion in the direction of lamination of the coils, and that constitutes a coil end portion, in which deterioration in insulation between wires of a coil is suppressed by disposing inner peripheral portions of the first bent portion and the second bent portion such that positions thereof are offset from each other in a flat face direction of the rectangular conductor wire only in the coil end portion, and also by preventing portions of the rectangular conductor wire in which bulging portions that arise due to compressive stresses due to bending are adjacent from facing each other in inner peripheral portions (see Patent Literature 1, for example).